1. Field of the Invention
The present invention relates to a stator structure, and in particular, to an improved stator structure employing magnetism to achieve balancing of a motor stator so as to reduce vibration thereof.
2. Description of the Related Art
Common motors mainly comprise two parts, a stator and a rotor. The rotation of the motor is caused by the alternating variations of magnetic fields acting the stator to drive the rotor to rotate. A rotating shaft coupled to the stator via a bearing is used to support the rotor to rotate about the center line of the rotating shaft.
However, there are clearances in the bearing no matter what the type of the bearings is. These clearances can cause vibrations when the rotor rotates at a high speed. Due to the vibrations, the working efficiency of the motor is lowered, and the longevity of the motor is shortened.
FIG. 1 is a schematic view showing a conventional motor stator structure 100 comprising a magnetically conductive cylinder 101, an upper pole layer 102, a lower pole layer 103, an insulating layer 810 and a coil 820. The upper pole layer 102 is located on a first plane and is substantially in the shape of a ring, the internal side of the ring is mounted on the external side of the top end of the cylinder 101, and the external side of the ring is formed with a plurality of upper spaced apart tabs. The lower pole layer 103 is located on a second plane which is parallel to the first plane and is substantially in the shape of a ring, the internal side of the ring is mounted on the external side of the bottom end of the cylinder 101, and the external side of the ring is formed with a plurality of lower spaced apart tabs. Viewed from over the motor stator structure 100, the upper spaced apart tabs 102 and the lower spaced apart tabs 103 are complementary. The insulating layer 810 is mounted between the upper pole layer 102 and the lower pole layer 103 and is mounted on the magnetically conductive cylinder 101. The coil 820 is winding on the insulating layer 810.
FIG. 2 is a schematic view showing engagement of the rotor with the above mentioned conventional motor stator structure. In FIGS. 1 and 2, like numerals refer to like components. The rotor 700 comprises a body 701, a rotating shaft 702 connected to the center of the body 701; and a magnetic belt 703 circularly arranged at the internal circumference of the body 701. A bearing 830 is provided between the internal surface of the magnetically conductive cylinder 101 and the rotating shaft 702 such that the rotor 700 rotates about the center line of the stator 100. The position of the magnetic belt 703 is corresponding to that of the coil 820. Thus, the change of direction of the magnetic fields produced by the coil 820 interacts with the magnetic belt 703 and causes the entire rotor 700 to rotate.
The drawback of the above conventional stator structure lies in that the magnetic conduction portion of the stator is constituted by three components, that is, the magnetically conductive cylinder, the upper pole layer and the lower pole layer, and the connection area of the magnetically conductive cylinder and the upper, lower pole layer affects the magnetically conductive effect. Further, in the process of connecting, the magnetically conductive cylinder or the upper, lower pole layer may be easily broken due to inappropriate mounting force.
FIG. 3 is a schematic view showing another conventional stator structure 200, wherein the insulating layer and the coil are similar to those as shown in FIG. 1 and are denoted with like numerals. The stator structure 200 comprises a ring 201, a plurality of upper spaced apart tabs 202, a plurality of lower spaced apart tabs 203, a plurality of waist posts 204, an insulating layer 810, and a coil 820. The plurality of upper spaced apart tabs 202 are connected at the external side of the ring 201, which defines an upper plane. The lower spaced apart tabs 203 are spaced apart from the ring 201, are complementary to the plurality of upper spaced apart tabs 202 when viewed from over the stator structure 200, and are provided on a second plane which is parallel to the first plane. The waist posts 204 are located between the first plane and the second plane. Each of the waist posts 204 has one end connected with the connection area of the corresponding one of the plurality of the upper spaced apart tabs 202 and the ring 201 and has the other end connected at the inner end of the lower spaced apart tabs 203 so as to form a magnetically conductive path. The insulating layer 810 is positioned between the upper spaced apart tabs 202 and the lower spaced apart tabs 203, and on the waist posts 204. The coil 820 winds on the insulating layer 810.
FIG. 4 is a schematic view showing the engagement of the rotor with the conventional stator structure, wherein the rotor is similar to that as shown FIG. 2. In FIGS. 2 to 4, like numerals refer to like components.
The rotor 700 comprises a body 701; a rotating shaft 702 connected to the center of the body 701, and a magnetic belt 703 mounted on the internal circumference of the body 701. A bearing 830 is provided in between the rotating shaft 702 and the inner surfaces of the waist posts 204 such that the rotor 700 rotates about the center line of the stator 200. The position of the magnetic belt 703 is corresponding to that of the coil 820. Thus, the change of direction of the magnetic fields produced by the coil 820 and the induction of the magnetic belt 703 cause the entire rotor 700 to rotate.
The advantage of the conventional art is that the magnetically conductive path is integrally formed as a unit which can enhance the effect of the magnetic conduction. However, the conventional art have not solved the defect of vibration caused by the clearances as a result of the connection between the rotor and the stator by means of a bearing.
Accordingly, it is an object of the invention to provide a stator structure which can reduce vibration caused by the rotor which rotates at high speed so that the working efficiency of the motor is improved and the longevity of the motor is extended.
One aspect of the present invention is to provide a stator structure comprising a plurality of upper spaced apart tabs substantially circularly arranged and formed on a first plane; and a plurality of lower spaced apart tabs substantially circularly arranged, complementary to the upper spaced apart tab when viewed from over the stator structure, and formed on a second plane parallel to the first plane, characterized in that the outer portion of each of the plurality of lower spaced apart tabs or upper spaced apart tabs extends to a position below or above the magnetic belt of the rotor so as to employ the magnetic force generated by the magnetic belt and lower spaced apart tabs or upper spaced apart tabs to maintain balancing of the rotor while rotating.
Another object of the present invention is to provide a stator structure, wherein apart from using a bearing to connect the stator and the rotor, the magnetic force around the rotor and the stator is additionally employed to maintain the rotating balancing of the rotor. Thus, the vibration due to the clearances of the bearings, when the motor rotates, can be greatly reduced. At the same time, the stator structure has not been changed, and therefore there is no need any more to provide any additional addition component or manufacturing process for maintaining the balancing of the rotor.